The present invention relates to methods for automatic recognition of particular types of information appearing on a printed master, and in particular to a method for automatic recognition of white blocks as well as text, graphics and/or gray image areas on a printed master.
Automatic word processing units are increasingly being employed in office use for producing, modifying and storing written documents in an economic and time-saving manner. Such units have the capability of undertaking error corrections, insertion of new text passages, combining two or more texts having different origins, and random reproduction and electronic storage of the data corresponding to the text passages. The advantages of such automatic word processing units in comparison to conventional typewriters are the flexibility and time-saving in the production of written documents which can be generated by such units, and the higher efficiency resulting therefrom. A particularly time consuming step associated with the use of automatic word processing units is the transfer of information already existing on paper into the automatic word processing unit for storage and/or further processing. Manual transfer by keyboard of large amounts of text is extremely time consuming and accordingly various methods and devices have been developed for automatically transferring the information contained in texts into the word processing unit.
A problem in the automatic transfer of existing information contained in text passages into a word processing unit is that the master on which the text passages occur may also contain graphics and/or image areas. It is a problem in the art to automatically identify, classify and store these different types of information areas on a master in order to achieve an optimum coding of the data representing these different master areas as well as to permit separate manipulation of the data representing those areas within the word processor.